Question

I have a field defined :

[Field, FullText("English")]
         public string Html { get; set; }

I have checked the postgres config and the free text config is setup.

I am getting the following error on domain build and not sure what it means:

TestFixture failed: Xtensive.Storage.DomainBuilderException : Unable to build full-text indexes for hierarchy 'NNet.Model.Content.Content' with InheritanceSchema.ClassTable. at Xtensive.Storage.Building.Builders.IndexBuilder.BuildFullTextIndexesClassTable(TypeInfo root, IEnumerable`1 hierarchyIndexes) at Xtensive.Storage.Building.Builders.IndexBuilder.BuildFullTextIndexes() at Xtensive.Storage.Building.Builders.IndexBuilder.BuildIndexes() at Xtensive.Storage.Building.Builders.ModelBuilder.BuildModel() at Xtensive.Storage.Building.Builders.ModelBuilder.Run() at Xtensive.Storage.Building.Builders.DomainBuilder.BuildModel() at Xtensive.Storage.Building.Builders.DomainBuilder.BuildDomain(DomainConfiguration configuration, DomainBuilderConfiguration builderConfiguration) at Xtensive.Storage.Upgrade.UpgradingDomainBuilder.BuildStageDomain(UpgradeStage stage) at Xtensive.Storage.Upgrade.UpgradingDomainBuilder.Build(DomainConfiguration configuration) at Xtensive.Storage.Domain.Build(DomainConfiguration configuration) at NNet.Model.Test.AutoBuildTest.BuildDomain(DomainConfiguration configuration) in D:\Project\NNet-Web\NNet-Model-Test\AutoBuildTest.cs:line 37

full code :

namespace NNet.Model.Content.Article {

    class Article : Content {

        [Field, LengthConstraint(Min = 2, Max = 50), NotNullOrEmptyConstraint]
        /// <summary>Title of Article</summary>
        public string Title { get; set; }

        [Field, LengthConstraint(Min = 2, Max = 150), NotNullOrEmptyConstraint]
        /// <summary>Summary of Article</summary>
        public string Summary { get; set; }

        [Field, FullText("English")]
        /// <summary>Article content</summary>
        public string Html { get; set; }

    }
}

namespace NNet.Model.Content {
    [HierarchyRoot]
    class Content : Entity {
        [Field, Key]
        public long Id { get; private set; }
    }
}

This thread was imported from our support forum. The original discussion may contain more detailed answer.

Answer 1

There is really the following restriction:

if (hierarchyIndexes.Any(fti => fti.Type.UnderlyingType != root.UnderlyingType) || indexesToDefine.Count > 1)
        throw new DomainBuilderException(string.Format(Strings.ExUnableToBuildFulltextIndexesForHierarchyWithInheritanceSchemaClassTable, root.Name));

I.e. full-text indexes can be declared only in hierarchy root types for class-table inheritance schema. Other inheritance schemas don't have this limitation. I'll ask the guys why it is enforced here - there must be some strong reasons for this.

Ok, so I got the explanation.

There are two important rules that determine such behavior:

Query.FreeText<t>(...) must return all the suitable descendants of T as well. I.e. we expect that Query.FreeText<tbase>(condition).Where(match => match.Entity is TDescendant).Select(match => match.Entity) returns the same set of entities as Query.FreeText<tdescandant>(condition).Select(match => match.Entity).
Placing [FullText] on a field means it will be included into full-text index that is bound to table related to this type.

Now note that we have 3 cases based on inheritance mapping strategy:

SingleTable: ideal case, since all the fields are included into the only full-text index for the whole hierarchy. So query for any T there will use this index; further we'll filter results based on Entity.TypeId - that's it.
ClassTable: good case as well, but only if all full-text fields (and thus - full-text index) are declared in hierarchy root. Otherwise query like Query.FreeText<cat>("mammal") won't return most of Cats, because "Mammal" is value of Animal.Class field (full-text indexed as well), but its index is bound to Animal-related table, but not Cat-related table. So in this case rule 1 is is broken, and the only way to satisfy it is to support full-text fields on hierarchy root only.
ConcreteTable: bad case, since there is no way to enforce this at all. I think now you'll easily conclude, why. Btw, currently it's allowed to create full-text indexes here, although we consider disabling this case at all, since rule 1 is anyway broken in this case: currently Query.FreeText<t>(...) here returns only entities with exact type T.

Subscription:

Related questions